replace a grandstream 3504 video server

For this purpose, we would always recommend Axis video servers - they are high-quality, reliable devices. Axis make some 4-channel servers (e.g. the 241Q, M7104) as well as some models with higher numbers of inputs (291 1U, P72).

However, analog cameras are very low quality by today's standards. Before spending money in order to support them, you should consider replacing them with modern IP cameras. If running new cables is the main barrier here, there are some solutions that allow you run IP networks over legacy coax cabling - let me know if you would like more information about this.

Running new cables certainly sounds like a difficult and unpleasant job!

One good solution we have come across is the POE IP Over Coax Solution from Linovision. You can use this in combination with PoE IP cameras, thereby keeping your existing cabling while providing far better resolution and quality than analog cameras. This may cost a bit more than keeping your existing analog cameras going, plus you have to install new cameras, but you'll end up with a far better result.

A few options:

1. Get an EOC-Converter transmitter + receiver pair for each camera ($75 per pair). The transmitter plugs into the camera and the receiver plugs into a standard PoE switch (e.g. Netgear, TP-Link etc.).

2. Get an EOC-Switch24 switch ($400). For each camera, you will need a passive adapter ($9) and active transmitter ($44). You can use any standard PoE IP camera.

3. Get an EOC-Switch24 ($400) or a Dahua ePoE switch ($300 for the 8-port version), and use a pair of passive Linovision or Dahua adapters ($18 per pair) for each camera. You must specifically use Dahua ePoE IP cameras for this to work - no other IP camera.

The EOC-Switch24 is a 24-port switch, so can be used to connect other devices on your network as well. However note that most of its ports are megabit speed (100 Mbps max) and not gigabit speed. Megabit is fine for IP cameras, so this switch would be perfect for connecting further standard PoE IP cameras in the future, but I would recommend that the rest of your network should be gigiabit if possible.

It may be possible to use a Dahua ePoE switch with the Linotype active transmitters in order to use any PoE IP camera, but it's not clear whether this is a supported configuration, so if you want to explore this, it's best to ask Linovision whether this will work.

The above options can be summarised by these images from Linovision:

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